Mineral wool products (also termed mineral fibre products) generally comprise man-made vitreous fibres (MMVF) such as, e.g., glass fibres, ceramic fibres, basalt fibres, slag fibres, mineral fibres and stone fibres (rock fibres), which are bonded together by a cured thermoset polymeric binder material. For use as thermal or acoustical insulation products, bonded mineral fibre mats are generally produced by converting a melt made of suitable raw materials to fibres in conventional manner, for instance by a spinning cup process or by a cascade rotor process.
The binder material may be applied to the mineral fibres immediately after the fibres are formed. Alternatively the binder material is applied to the mineral fibres in an off-line process separate from the fibre forming process. The binder material in the latter case is traditionally a solid-state binder which is not in a diluted aqueous solution. Such binders are referred to as dry binders. Mineral fibre products with dry binders are formed by mixing the mineral fibres and the binder material to form a mixture and applying heat and pressure to the mixture in a plate press apparatus to provide a cured mineral fibre product. A conventional dry binder material is a phenol-formaldehyde resin with a hardener material. Other binders are being developed to avoid the emission of formaldehyde.
Since some of the starting materials used in the production of the known binders are rather expensive chemicals, there is an ongoing need to provide formaldehyde free binders which are economically produced and at the same time show good bonding properties for producing a bonded mineral fibre product.
A further effect in connection with previously known binder compositions from mineral fibres is that at least the majority of the starting materials used for the productions of these binders stem from fossil fuels. There is an ongoing trend of consumers to prefer products that are at least partly produced from renewable materials and there is therefore a need to provide binders for mineral wool which are at least partly produced from renewable materials.
Further, there is an ongoing need to provide binders for mineral wool which enable the production of mineral wool products having good long term mechanical properties.